Problem about tcp_alloc_pskb()
I have a problem I can't solve it.
I am developing a module on SUSE 9(kernel-2.6.5). In my module, I will find a socket which is established in another process, by pid and fd. Then I will send data by this socket.
In the mysend(), call kernel routine, from sock_sendmsg()->tcp_sendmsg()->tcp_alloc_pskb(). but tcp_alloc_pskb() always returns NULL, instead of a proper sk_buff. BTW, system call send() calls sock_sendmsg()->tcp_sendmsg()->tcp_alloc_pskb() in the same way, but it can does work well.
So I ask for help or some other cluds or hints? Or how to debug it in a efficient way? Thanks a lot.